Document Type
Thesis - University Access Only
Award Date
2012
Degree Name
Master of Science (MS)
Department / School
Geography
First Advisor
Geoffrey M. Henebry
Abstract
Perhaps because the fate of the crop stand has already been determined by the time of its occurrence, little attention has been given to the brown-wave phase of phenology, senescence. As with the other phases of the phenological process, the events that initiate and compose senescence are closely related to phenomena in the lower atmosphere. For 40 years, making use of satellite-borne spectrometers, the scientific community has had the ability to monitor these climatological phenomena and observe their effects on the biosphere, thereby greatly advancing the field of phenology. Various spectral indices have been developed by mathematically combining different bands ( observations recorded from the canopy using a specific interval of the electromagnetic spectrum); each index seeks to explain a different aspect of the canopy. The dynamics of senescence of maize and soy canopies as characterized by these spectral indices carry broad implications for much of the earth's mid-latitudes, where these crops are grown. The objective of this research is to identify methods of describing senescence at the field level by employing combinations of spectral indices available using bandwidths available in the Landsat series. Results indicate cases exist in which combining NDVI and NDII may prove useful. Another index, NExG, is also shown to be too susceptible to low signal-to-noise ratios to be useful with orbital instruments.
Library of Congress Subject Headings
Corn -- Aging Soybean -- Aging
Plant canopies -- Remote sensing
Publisher
South Dakota State University
Recommended Citation
Helder, Benjamin, "Characterizing Maize and Soy Senescence by Divergence of Multiple Spectral Indices" (2012). Electronic Theses and Dissertations. 1930.
https://openprairie.sdstate.edu/etd2/1930
Rights Statement
